All-Carbon Quaternary Centers via Ruthenium-Catalyzed Hydroxymethylation of 2-Substituted Butadienes Mediated by Formaldehyde: Beyond Hydroformylation
作者:Tomas Smejkal、Hoon Han、Bernhard Breit、Michael J. Krische
DOI:10.1021/ja904124b
日期:2009.8.5
Ruthenium-catalyzed transfer hydrogenation of 2-substituted dienes 1a-i in the presence of paraformaldehyde results in reductive coupling at the 2-position to furnish the hydroxymethylation products 3a-i, which embody all-carbon quaternary centers. Reductive coupling of diene 1g to paraformaldehyde under standard conditions, but employing deuterio-paraformaldehyde, 2-propanol-d(8), or both, corroborated
在多聚甲醛存在下,2-取代二烯 1a-i 的钌催化转移氢化导致 2 位还原偶联,得到羟甲基化产物 3a-i,其包含全碳四级中心。在标准条件下将二烯 1g 还原偶联至多聚甲醛,但使用氘代多聚甲醛、2-丙醇-d(8) 或两者,证实了一种催化机制,涉及快速、可逆的二烯氢金属化,在 CC 偶联之前具有不完全的区域选择性。本方法提供了共轭二烯加氢甲酰化的替代方案,对此有效的区域选择性催化系统仍未开发。